A comparative study of dentoskeletal changes of Herbst appliance treatment among different skeletal maturity groups based on cervical vertebral maturation

Abstract

The aim of the present study was to evaluate the sagittal skeletal and dentoalveolar changes produced by a splinted Herbst appliance in three groups of Chinese subjects with a Class II malocclusion treated at different stages of skeletal maturity (Before, during and after the pubertal peak of growth) as determined by the cervical vertebral maturation (CVM). The pre-peak group consisted of 20 subjects (8 females and 12 males) presenting with stage 2 in CVM (Mean age 9.8 ± 2.1 years). The peak group consisted of 25 subjects (13 females and 12 males) presenting with either stages 3 or stage 4 in CVM (mean age 13.3 ± 1.5 years). The post-peak group consisted of 22 subjects (11 females and 11 males) presenting with either stage 5 or stage 6 in CVM (mean age 18 ± 2.4 years). Lateral cepahlograms taken at the start (T1) and the end (T2) of treatment with a splinted Herbst appliance were analysed using sagittal occlusal analysis of Pancherz. One-way ANOVA revealed that pre-peak and peak groups exhibited a significant improvement of molar relationship (P <0.05) compared with the post-peak group. The peak group exhibited a significant improvement (P <0.05) of advancement of the mandibular base compared with the pre and post-peak groups. The post-peak group exhibited more proclination of the lower incisors than the pre-peak and peak groups (P <0.05). The results suggest that treatment of skeletal Class II malocclusion with the Herbst appliance is best during the peak growth spurt corresponding to CVM Stage 3-4.